You are confused.
The only thing you need with Katalon is, to bring propper jars to solve the deps for your custom codes.
How you do that is up to you.
There may be some examples here and there how to achive that with Graddle or other tools, but here the magic ends.
Katalon cannot integrate currently with any tool like maven or graddle or whatever else simply because is out of scope.
You can locate any external libraries in the <projectDir>/Drivers folder. Katalon Studio recognizes these jars and bring them accessible for the user codes. See the following doc. This is the principal way for users to import the external dependencies into a Katalon project.
This approach could be problematic when you imported multiple jar versions of a single OSS project, as the following post discusses:
I wanted to use the latest version 2.13.0 of commons-io, while the older version 2.6.0 of commons-io was bundled in the distributable Katalon Studio. Katalon Studio primarily refers to the bundled older version.
Katalon provides a way to exclude the budled jar to prefer another jar in the Drivers folder, but this fails when you run your project on a remote server with KRE as CI/CD pipeline. This post reported it.
In my humble opinion, Katalon’s approach for external dependencies is a stopgap measure. It can not solve the problems of complex external dependencies that continues bening upgraded. If you are an experienced Java/Groovy programmer and seriously require the Maven/Gradle’s feature of dependency management, you should consider graduating KS/KRE. You are able to build your project on top of Gradle + WebDriver natively without Katalon, aren’t you?